They believe their duty is to usher in the apocalypse. It will come by way of conquering the heart of the eastern Roman empire (Constantinople, modern day Istanbul) then dying en masse by hand of the armies of the anti-Messiah. Only after they're nearly defeated will Allah usher in his apocalyptic salvation.

http://www.theatlantic.com/magazine/...-wants/384980/

Executions and enslavement of innocents are continual. They need to be invaded yesterday. Every last one with a bullet between his eyes.